1. Field of the Invention
The invention is directed to a rotor bearing for an electrical machine, particularly to a disk armature generator for generating electrical energy from the rotational energy of a power installation driven in rotation, preferably a turbine power installation, particularly a wind power installation, comprising at least two stator components that are mutually offset axially along a generally horizontal rotation axis of a disk armature, and comprising, mounted therebetween on a single rolling bearing so as to rotate about the rotation axis, at least one ring- or disk-shaped rotor component of the disk armature, and to a wind power installation equipped in such manner.
2. Description of the Prior Art
Rotating installation parts and machine parts are often mounted by means of rolling bearings. For example, in unexamined German patent application DE 10 2004 021 138 A1 there is described an electrical machine and its mounting in which the fixed bearing is implemented as two deep groove ball bearings. In this type of design, the rotatable shaft is mounted at two different points, on a so-called “fixed bearing” and a so-called “loose bearing”. However, a multiple bearing of this kind is a relatively expensive way to deal with large rotating masses, since in such cases the rolling bearings must be of correspondingly massive construction and are therefore cost-intensive to design and build.
Particularly, in a wind power installation, the shaft driven by the wind energy, which shaft is oriented along the main rotor axis, should be mounted to ensure that operation is as frictionless as possible, so that the energy extracted from the motive force of the wind can be transferred and converted with the lowest possible losses.
Thus, for example, unexamined patent application DE 10 2009 004 991 A1 addresses the mounting of the rotor of a wind power installation whose rotor points approximately in the wind direction. The proposed mounting includes at least two annular, mutually concentric elements for connection to oppositely rotatable system components of the wind power installation, specifically to its rotor or to the output shaft of a gearbox coupled thereto, on the one hand, and to the chassis of the nacelle, on the other hand. The force of the wind preferably drives, via a gear stage, a shaft that is coupled to other components at the output end.
The problem of mounting a rotating shaft also arises in the context of electrical machines used to convert rotational energy into electrical energy.
Thus, for example, DE 10 2007 037 842 A1 discloses an electrical machine in the category of a centrally mounted disk armature, configured as a disk armature having a stator and a disk-shaped rotor. The stator in this case comprises at least one disk-shaped stator part disposed on a holder and spaced apart from the rotor in the axial direction so as to interact magnetically with the rotor across an air gap, wherein the rotor is mounted on a holder rotatably about its own rotation axis. For connection on the input side, the generator has an input shaft, but the only way to connect this input shaft to the output shaft of a gearbox, or the like, is by butt flanging. Such a shaft connection makes it impossible to position the generator and a gear, or the like, closer together, since the shaft connection would then be inaccessible. Since space is at a premium, particularly in wind power installations, such a generator cannot be used advantageously in such facilities.